soxr-code/INSTALL

SoX Resampler Library       Copyright (c) 2007-16 robs@users.sourceforge.net

INSTALLATION GUIDE CONTENTS

* Standard build
* Build customisation
* Cross-compilation
* Integration with other build systems
* Run-time configuration



STANDARD BUILD

1. Prerequisites:

    Before you can build this library, you need to have available on your
    system:

    * A C-compiler with 64-bit integer support and, optionally, OpenMP, SIMD.

    * A 'make' utility (most compiler installations already have one of these).

    * CMake: https://cmake.org/download/


2. Build:

    At a command prompt, change directory (`cd') to the one containing this
    file, then enter:

        go                          (on MS-Windows with nmake)
    or
        ./go                        (on Unix-like systems)

    This should build the library and run a few sanity tests.


3. Installation:

    Note that this step may need to be performed by a system
    administrator.  Enter:

        nmake install               (on MS-Windows)
    or
        cd Release; make install    (on Unix-like)


4. Preparation for use:

    To use the library you may need to set up appropriate paths to the
    library and its header file in your development environment.


5. Installation test

    To test the installation, build and run some of the example programmes
    (see examples/README).



BUILD CUSTOMISATION

If it is necessary to customise the build, then steps 2 and 3 above may be
substituted as follows.  Change directory to the one containing this file,
then enter commands along the lines of:

    mkdir build
    cd build
    cmake [OPTIONS] ..
    make
    make test
    sudo make install

To list help on the available options, enter:

    cmake -LH ..

Options, if given, should be preceded with '-D', e.g.

    cmake -DWITH_SIMD:BOOL=OFF ..



Resampling engines

As available on a given system, the library may include up to four resampling
‘engines’, as follows:

    cr32: for constant-rate resampling with precision up to 20 bits,
    cr32s: SIMD variant of cr32,
    cr64: for constant-rate resampling with precision greater than 20 bits,
    vr32: for variable-rate resampling.

Engine inclusion is controlled (as above) by the following cmake option
variables:

    cr32: WITH_SINGLE_PRECISION
    cr32s: WITH_SINGLE_PRECISION, WITH_SIMD
    cr32: WITH_DOUBLE_PRECISION

By default, these variables are all set to ON.

When both cr32 and cr32s engines are included, run-time selection is automatic
(based on CPU capability) for x86 CPUs, and can be automatic for ARM CPUs if
the 3rd-party library `libavutil' is available at libsoxr build-time.



CROSS-COMPILATION

E.g. targeting a Linux ARM system:

    mkdir build
    cd build
    cmake -DCMAKE_SYSTEM_NAME=Linux \
          -DCMAKE_C_COMPILER=arm-linux-gnueabi-gcc-5 \
          ..
or, also building the examples (one of which uses C++):

    cmake -DCMAKE_SYSTEM_NAME=Linux \
          -DCMAKE_C_COMPILER=arm-linux-gnueabi-gcc-5 \
          -DCMAKE_CXX_COMPILER=arm-linux-gnueabi-g++-5 \
          -DBUILD_EXAMPLES=1 \
          ..

E.g. with Mingw (Linux host), using a tool-chain file:

    mkdir build
    cd build
    cmake -DCMAKE_TOOLCHAIN_FILE=~/Toolchain-x86_64-mingw-w64-mingw32.cmake \
          -DCMAKE_INSTALL_PREFIX=install \
          ..
    make

where ~/Toolchain-x86_64-mingw-w64-mingw32.cmake might contain:

    SET(CMAKE_SYSTEM_NAME Windows)
    SET(CMAKE_C_COMPILER /usr/bin/x86_64-w64-mingw32-gcc)
    SET(CMAKE_CXX_COMPILER /usr/bin/x86_64-w64-mingw32-g++)
    SET(CMAKE_RC_COMPILER /usr/bin/x86_64-w64-mingw32-windres)
    SET(CMAKE_Fortran_COMPILER /usr/bin/x86_64-w64-mingw32-gfortran)
    SET(CMAKE_AR:FILEPATH /usr/bin/x86_64-w64-mingw32-ar)
    SET(CMAKE_RANLIB:FILEPATH /usr/bin/x86_64-w64-mingw32-ranlib)
    SET(CMAKE_FIND_ROOT_PATH /usr/x86_64-w64-mingw32)
    SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
    SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
    SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
    SET(QT_BINARY_DIR /usr/x86_64-w64-mingw32/bin /usr/bin)
    SET(Boost_COMPILER -gcc47)



INTEGRATION WITH OTHER BUILD SYSTEMS

Autotools-based systems might find it useful to create a file called
`configure' in the directory containing this file, consisting of the line:
    cmake -DBUILD_SHARED_LIBS=OFF .
(or with other build options as required).

For MS visual studio, see msvc/README.



RUN-TIME CONFIGURATION

The libsoxr API structure ‘soxr_runtime_spec_t’ allows application developers
to optimise some aspects of libsoxr’s operation for a particular application.
However, since optimal performance might depend on an individual end-user’s
run-time system and the end-user’s preferences, environment variables are
available to set (override) the run-time parameters:

    Env. variable        Equivalent soxr_runtime_spec_t item
    ------------------   -----------------------------------
    SOXR_COEFS_SIZE      coef_size_kbytes
    SOXR_COEF_INTERP     SOXR_COEF_INTERP_xxx
    SOXR_LARGE_DFT_SIZE  log2_large_dft_size
    SOXR_MIN_DFT_SIZE    log2_min_dft_size
    SOXR_NUM_THREADS     num_threads

Additionally, the SOXR_USE_SIMD environment variable may be used to override
automatic selection (or to provide manual selection where automatic selection
is not available) between the cr32 and cr32s resampling engines. (Which engine
is selected for a specific configuration of libsoxr can be checked using
example #3, which reports it.)